Radially-firing electrohydraulic lithotripsy probe

ABSTRACT

Invasive side-firing electrohydraulic lithotripsy probes that creates a substantially annular shockwave to break up concretions are disclosed. Generally, the side-firing electrohydraulic lithotripsy probe includes a lithotripter tip including a first electrode and a second electrode. The first electrode is positioned at a distal end of the lithotripter tip and the second electrode is positioned in the lithotripter tip such that an end of the second electrode is coaxially aligned with an end of the first electrode. An electric arc between the first and second electrodes causes a shockwave to radiate radially from the lithotripter tip.

RELATED APPLICATIONS

The present application claims priority to U.S. patent application Ser.No. 12/436,547 (still pending), filed May 6, 2009, which claims priorityto U.S. Provisional Patent Application No. 61/051,262 (still pending),filed May 7, 2008, the entirety of each of which are hereby incorporatedby reference.

BACKGROUND

Electrohydraulic lithotripsy has been used in the medical field,primarily for breaking concretions in the urinary or biliary track.Conventional lithotripsy probes produce a shockwave that radiatesaxially from a distal end of the lithotripsy probe. While a shockwaveradiating axially from a distal end of a lithotripsy probe is useful inbreaking up concretions such as a kidney stone, it is often difficult touse these types of probes to break up annular concretions, such asconcretions around a heart valve. Accordingly, improved lithotripsyprobes are desirable for breaking up concretions that are not locatedaxially from a distal end of a lithotripsy probe.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a radially-firingelectrohydraulic lithotripsy probe;

FIG. 2 is a cross-sectional side view of the radially-firingelectrohydraulic lithotripsy probe of FIG. 1;

FIG. 3 is a perspective view of another embodiment of a radially-firingelectrohydraulic lithotripsy probe;

FIG. 4 is a cross-sectional side view of the radially-firingelectrohydraulic lithotripsy probe of FIG. 3;

FIG. 5 is a perspective view of another embodiment of a radially-firingelectrohydraulic lithotripsy probe;

FIG. 6 is a cross-sectional side view of the radially-firingelectrohydraulic lithotripsy probe of FIG. 5;

FIG. 7 is a side view of the radially-firing electrohydrauliclithotripsy probe of FIG. 5;

FIGS. 8a and 8b are a cross-section of an EHL probe including a fusiblelink;

FIG. 8c is a flow chart for a method of using the EHL probe of FIG. 8 a;

FIGS. 9a and 9b are a cross-section of an EHL probe including a smartmemory chip;

FIG. 9c is a flow chart of a method for using the EHL probe of FIG. 9 b;

FIGS. 10a and 10b are a cross-section of an EHL probe including afusible link and a smart memory chip;

FIG. 10c is a flow chart of a method for using the EHL probe of FIG. 10b;

FIGS. 11a and 11b are a cross-section of an EHL probe including a firstfusible link and a second fusible link;

FIG. 11c is a flow chart of a method for using the EHL probe of FIG. 11a;

FIG. 12 is a side view of a reinforced EHL probe; and

FIGS. 13a, 13b, 13c, and 13d illustrate enlarged views of a rounded tipof an EHL probe.

DETAILED DESCRIPTION OF THE DRAWINGS

The present disclosure is directed to an invasive radially-firingelectrohydraulic lithotripsy probe that creates a substantially annularshockwave for uses such as breaking up concretions that are at leastsemi-annular or disrupting tissue of a body organ. Generally,embodiments of the disclosed radially-firing electrohydrauliclithotripsy (“EHL”) probes include a first electrode at a distal end ofthe probe, and a second electrode coaxially aligned with the firstelectrode. A difference in voltage polarities between the first andsecond electrodes causes an electric arc, resulting in a shockwave thatis at least semi-annular that radiates radially from the lithotripsyprobe.

In one implementation, the EHL probes described below may be deliveredto a proper channel of a heart by threading (or pre-loading) an EHLprobe through a center lumen of a catheter or balloon device. Thecatheter may be threaded through appropriate veins or arteries toaddress concretions either forming in vessels or even in the valves ofthe heart or other organs.

In other implementations, the EHL probes described below may bedelivered to a small lumen of a body organ for the purpose of disturbingor disrupting (distressing) tissue of the body organ in such a way as tocause a stricture or a “scarring” of the tissue for the purpose ofcreating a permanent stricture or blockage of the lumen. For example,the EHL probes described below may be used to purposely create ablockage in a fallopian tube for the purpose of preventing pregnancies(sterilization). A fallopian tube, which is approximately 1 mm indiameter, would have one of the EHL probes described below threaded intoit. The EHL probe may be threaded through the fallopian tube(s) toaddress the inner surface of the fallopian tube. Upon generating the EHLspark and subsequent pressure wave in a radial manner, a rupturing ordisrupting of the walls of the inner surface of the fallopian tube canbe accomplished. The subsequent healing or scarring of the walls causethe walls of the inner surface of the fallopian tube to knit togetherand create a blockage that renders the fallopian tube non-functional,thereby sterilizing a patient and preventing pregnancies.

Referring to FIGS. 1 and 2, one embodiment of a radially-firing EHLprobe 100 (the “probe 100”) includes a lithotripsy probe tip 101including an insulating body 102, a first electrode 104, and a secondelectrode 106. Typically, the first electrode 104 is positioned at afirst distal end 108 of the lithotripsy probe tip 101. In oneimplementation, the first electrode 106 is conic in shape and includesan electrically conductive material such as copper, silver, or stainlesssteels. However, the first electrode 106 may be other shapes such as acurved surface and/or made of other electrically conductive material.

The first electrode 104 is supported by a plurality of wires 110extending from the first distal end 108 of the lithotripsy probe tip101. The plurality of wires 110 are made of an electrically conductivematerial, such as copper, silver, stainless steel, or other conductivematerials, and electrically coupled with a first electrically conductivestructure 112 in the EHL probe 100. Typically, the plurality of wires110 are insulated other than where the plurality of wires 110 areelectrically coupled with the first electrode 104 and the firstelectrically conductive structure 112. As known in the art, the firstconductive structure 112 may be coupled with an electrical source, suchas an electrohydraulic generator (Autolith, Supplied by NorhgateTechnologies Inc.), used to charge the first electrode 104 to a firstpolarity.

The second electrode 106 is positioned in the body of the lithotripsyprobe tip 101. In one implementation, at least an end 114 of the secondelectrode 106 is cylindrical and includes an electrically conductivematerial such as copper, silver, stainless steel, or other conductivematerials. However, the second electrode 106 may be other shapes. Thesecond electrode 106 is positioned in the lithotripsy probe tip 101 suchthat the second electrode 106 is coaxially, and in some implementationssymmetrically, aligned with the first electrode 104. For example, whenthe first electrode 104 is conic in shape and an end 114 of the secondelectrode 106 is cylindrical, the first and second electrodes 104, 106are positioned such that an axis extending from the conic firstelectrode 104 is substantially aligned with an axis extending from thecylindrical portion of the second electrode 106.

In some implementations, a distance between a tip of the first electrode104 and a point on the second electrode 106 closest to the firstelectrode is 0.021 inch. However, various distances between 0.006 and0.100 inch could be used depending on the application and the amount ofenergy to be transmitted.

The second electrode 106 is electrically coupled with a secondelectrically conductive structure 116 in the EHL probe 100. As known inthe art, the second electrically conductive structure 116 may be coupledwith an electrical source and used to charge the second electrode to asecond polarity, which is opposite to the first polarity of the firstelectrode 104.

In one implementation, the first electrode 104 is an anode and thesecond electrode 106 is a cathode, where in other implementations, thefirst electrode 104 is a cathode and the second electrode 106 is ananode. When the first electrode 104 is charged to a first polarity viathe first conductive structure 112 and the second electrode 106 ischarged to a second, opposite polarity via the second conductivestructure 114, a discharge of electricity occurs between the first andsecond electrodes 104, 106 (an electrical arc) when the potentialbetween the first and second electrodes 104, 106 reaches the breakdownvoltage for the media separating the electrodes.

In some implementations, such as the heart application described above,at least a portion of the lithotripsy probe tip 101 including the firstand second electrodes 104, 106 is surrounded by a flexible encapsulatingmember 118, such as a balloon, comprising a water-tight flexiblematerial such as Mylar. The flexible encapsulating member 118encapsulates a liquid such as saline. However, other liquids can beused. When an electrical arc occurs between the first and secondelectrodes 104, 106 as described above, the electrical arc causes asteam bubble in the liquid of the flexible encapsulating member 118. Thesteam bubble rapidly expands and contracts back on itself. As the steambubble contracts, a pressure wave (a shockwave) is created in the liquidof the flexible encapsulating member 118 that radiates away from thelithotripsy tip 101 in a substantially radial manner such that theshockwave is at least semi-annular. However, in other implementations, aflexible encapsulating member 118 does not surround the lithotripsyprobe tip 101.

Another embodiment of a radially-firing EHL probe is described belowwith respect to FIGS. 3 and 4. The radially-firing EHL probe 300 (the“probe 300”) includes a lithotripsy probe tip 301 including aninsulating body 302, a first electrode 304, and a second electrode 306.Similar to the embodiment described above with respect to FIGS. 1 and 2,the first electrode 304 is positioned at a first distal end 308 of thelithotripsy probe tip 301. The first electrode 304 is positioned on anend of a hook structure 310 extending from the first distal end 308 ofthe lithotripsy probe tip 301. The hook structure 310 may be othershapes that extend from the first distal end 308 of the lithotripsyprobe tip 301 and curve back towards the lithotripsy probe tip 301 sothat the first electrode 304 may be positioned at an end of thestructure 310 and coaxially aligned with the second electrode 306 asexplained in more detail below.

The hook structure 310 includes an electrically conductive material suchas copper, silver, stainless steel, or other conductive materials, andis electrically coupled with a first electrically conductive structure312 in the EHL probe 300. In some implementations, the hook structure310 is insulated other than where the hook structure 310 is electricallycoupled with the first electrode 304 and at the first electrode 304 Asknown in the art, the first electrically conductive structure 312 may beelectrically coupled with an electrical source and used to charge thefirst electrode 304 to a first polarity.

The second electrode 306 is positioned in body of the lithotripsy probetip 301. In one implementation, at least an end 314 of the secondelectrode 306 is cylindrical and includes an electrically conductivematerial such as copper, silver, stainless steel, or other conductivematerials. However, the second electrode 306 may be other shapes. Thesecond electrode 306 is positioned in the lithotripsy probe tip 301 suchthat the second electrode 306 is coaxially, and in some implementationssymmetrically, aligned with the first electrode 304. For example, whenan end 314 of the second electrode 306 is cylindrical, an axis extendingfrom the cylindrical portion of the second electrode 306 issubstantially aligned with the first electrode 304 positioned on thehook structure 310.

In some implementations, a distance between the first electrode 304 anda point on the second electrode 306 closest to the first electrode is0.021 inch. However, various distances between 0.006 and 0.100 inchcould be used depending on the application and the amount of energy tobe transmitted.

The second electrode 306 is electrically coupled with a secondelectrically conductive structure 316 in the EHL probe 300. As known inthe art, the second electrically conductive structure 316 may beelectrically coupled with an electrical source and used to charge thesecond electrode to a second polarity, which is opposite to the firstpolarity of the first electrode 304.

In one implementation, the first electrode 304 is an anode and thesecond electrode 306 is a cathode, where in other implementations, thefirst electrode 304 is a cathode and the second electrode 306 is ananode. When the first electrode 304 is charged to a first polarity viathe first electrically conductive structure 312 and the second electrode306 is charged to a second, opposite polarity via the secondelectrically conductive structure 314, a discharge of electricity occursbetween the first and second electrodes 304, 306 (an electrical arc)when the potential between the first and second electrodes 304, 306reaches the breakdown voltage for the media separating the electrodes.

In some implementations, at least a portion of the lithotripsy probe tip301 including the first and second electrodes 304, 306 is surrounded bya flexible encapsulating member 318, such as a balloon, comprising awater-tight flexible material such as Mylar. The flexible encapsulatingmember 318 encapsulates a liquid such as saline. However, other liquidscan be used. When an electrical arc occurs between the first and secondelectrodes 304, 306 as described above, the electrical arc causes asteam bubble in the liquid of the flexible encapsulating member 318. Thesteam bubble rapidly expands and contracts back on itself. As the steambubble contracts, a pressure wave (a shockwave) is created in the liquidof the flexible encapsulating member 118 that radiates away from thelithotripsy tip 301 in a radial manner such that the shockwave is atleast semi-annular. However, in other implementations, a flexibleencapsulating member 318 does not surround the lithotripsy probe tip301.

Yet another embodiment of a radially-firing EHL probe is described belowwith respect to FIGS. 5, 6, and 7. The radially-firing EHL probe 500(the “probe 500”) includes a lithotripsy probe tip 501 including aninsulating body 502, a first electrode 504, and a second electrode 506.The first and second electrodes 504, 506 are positioned on a side-firingstructure 508 of the lithotripsy probe tip 501. An axis of theside-firing structure 508 is typically angled approximately 90 degreesfrom the longitudinal axis of the lithotripsy probe 501 so that, asexplained below, the lithotripsy probe tip 501 may create a directedshockwave that radiates away from the lithotripsy probe tip 501 atapproximately a 90 degree angle from the longitudinal axis of thelithotripsy probe 501.

In one implementation, the first electrode 504 may be a cylindricalsleeve positioned on an exterior of the side-firing structure 508.However, the first electrode 504 may be other shapes. The firstelectrode 504 is electrically coupled with a first electricallyconductive structure 510 in the EHL probe 500. As known in the art, thefirst electrically conductive structure 510 may be electrically coupledwith an electrical source and used to charge the first electrode 504 toa first polarity.

The second electrode 506 is coaxially aligned with the first electrode504. In one implementation, the first electrode 504 is a cylindricalsleeve and the second electrode 506 is a cylindrical core that ispositioned within the interior of the first electrode 504 such that theaxis of the cylindrical sleeve of the first electrode 504 substantiallyaligns with the cylindrical core of the second electrode 506.

The second electrode 506 is electrically coupled with a secondelectrically conductive structure 512 in the EHL probe 500. As known inthe art, the second electrically conductive structure 512 may beelectrically coupled with an electrical source and used to charge thesecond electrode 506 to a second polarity, which is opposite to thefirst polarity of the first electrode 504.

In one implementation, the first electrode 504 is an anode and thesecond electrode 506 is a cathode, where in other implementations, thefirst electrode 504 is a cathode and the second electrode 506 is ananode. When the first electrode 504 is charged to a first polarity viathe first conductive structure 510 and the second electrode 506 ischarged to a second, opposite polarity via the second conductivestructure 512, a discharge of electricity occurs between the first andsecond electrodes 504, 506 (an electrical arc) when the potentialbetween the first and second electrodes 504, 506 reaches the breakdownvoltage for the media separating the electrodes.

In some implementations, at least a portion of the lithotripsy probe tip501 including the first and second electrodes 504, 506 is surrounded bya flexible encapsulating member 514, such as a balloon, comprising awater-tight flexible material such as Mylar. The flexible encapsulatingmember 514 encapsulates a liquid such as saline. However, other liquidscan be used. When an electrical arc occurs between the first and secondelectrodes 504, 506 as described above, the electrical arc causes asteam bubble in the liquid of the flexible encapsulating member 514. Thesteam bubble rapidly expands and contracts back on itself. As the steambubble contracts, a pressure wave (a shockwave) is created in the liquidof the flexible encapsulating member 514 that radiates away from theside-firing structure 508 in an axial manner, so that the shockwaveradiates away from the lithotripsy probe tip 501 in a radial manner.However, in other implementations, a flexible encapsulating member 514does not surround the lithotripsy probe tip 501.

One concern with EHL probes is a breakdown of the EHL probe, also knownas the End of Life of an EHL probe. In some implementations, anelectrical source such as an electrohydraulic generator connected to anEHL probe may track a number of times it fires an EHL probe. Based onthe number of times the EHL probe fires, power levels used during thefiring of the EHL probe, and historical End of Life data for EHL probes,the electrical source may then determine when the EHL probe is nearingEnd of Life.

When an EHL probe nears End of Life, an electrical source may displaymessages such as “End of Life” or “Change Probe” to warn a doctor todispose of an EHL probe. In some implementations, an EHL probe may bedesigned to disable the EHL probe after reaching or nearing End of Life.

FIGS. 8a and 8b are a cross-section of an EHL probe 804 including afusible link 802. Generally, the fusible link 802 is used to disable theEHL probe 804 when the EHL probe nears End of Life. In oneimplementation, the fusible link 802 may be placed in a connector 806 ofthe EHL probe 804. However, in other implementations, the fusible link802 may be placed in other portions of the EHL probe 804.

Generally, an electrical source 808 monitors a number of times the EHLprobe 804 fires and power levels used during firing of the EHL probe804. The electrical source 808 compares the number of times the EHLprobe 804 fires and power levels used during firing of the EHL probe 804to historical End of Life data for EHL probes. When the electricalsource 808 determines the EHL probe 804 is near End of Life, theelectrical source 808 send a short blast of high current to the EHLprobe 804. In one implementation, the short blast of high current is 150milliamps. When the short blast of high current reaches the fusible link802 in the EHL probe 804, the high current causes a fuse within thefusible link 802 to “open” (vaporizing some of the wire to open acircuit), thereby disabling the EHL probe 804. In some implementations,the fusible link 802 includes a sense resistor 803 placed between twopins, however other implementations do not include the sense resistor803.

In some implementations, the electrical source 808 may measure aninterior resistance of an EHL probe 804 so that the electrical source808 can determine when the EHL probe 804 has been disabled.

FIG. 8c is a flow chart of a method for using the EHL probe describedabove with respect to FIGS. 8aand 8b . At step 810 an electrical sourcemeasures an interior resistance of an EHL probe to determine whether theEHL probe has been disabled. The electrical source may perform step 810when the EHL probe is first connected to the electrical source,periodically, before each firing of the EHL probe, and/or after eachfiring of the EHL probe.

If the electrical source determines at step 810 that the EHL probe hasbeen disabled, the method proceeds to step 811 where the electricalsource displays a message such as “End of Life” or “Change Probe” towarn a doctor to dispose of the EHL probe. However, if the electricalsource determines at step 810 that the EHL probe has not been disabled,the method proceeds to step 812 where the electrical source monitors anumber of times an EHL probe fires and power levels used during firingof the EHL probe.

At step 814, the electrical source compares the number of times the EHLprobe has fired and the power levels used during firing of the EHL probeto historical End of Life data for EHL probes to determine whether theEHL probe is near End of Life. The electrical source may perform step814 periodically, before each firing of the EHL probe, and/or after eachfiring of the EHL probe.

If the electrical source determines at step 814 that the EHL probe isnot near End of Life, the method loops to step 812 and the electricalsource continues to monitor the number of times an EHL probe fires andpower levels used during firing of the EHL probe. However, if theelectrical source determines at step 812 that the EHL probe is near Endof Life, the method proceeds to step 816.

At step 816, the electrical source sends a short blast of high currentto the EHL probe to cause a fuse within the fusible link of the EHLprobe to open, thereby disabling the EHL probe. At step 818, theelectrical source may display a message such as “End of Life” or “ChangeProbe” to warn a doctor to dispose of the EHL probe.

It will be appreciated that the order of the one or more steps of themethod described with respect to FIG. 8c may be changed. Further, insome implementations, the method of FIG. 8c may be implemented inconjunction with a computer-readable storage medium comprising a set ofinstructions to direct a processor of the electrical source to performone or more of the above-described acts.

FIGS. 9a and 9b are a cross-section of an EHL probe 902 including asmart memory chip 904. The smart memory chip 904 may be any flash memorydevice small enough to be positioned in a connector of the EHL probe902. One example of such a flash memory device is a 128k×8 monolithicflash chip by White Electronics Designs Corp. (part numberWMF-128k8-xclx5). Generally, each time an electrical source 906 firesthe EHL probe 902, the electrical source 906 also sends a count signalto the smart memory chip 904. The smart memory chip 904 monitors anumber of times the EHL probe 902 has been fired. When the EHL probe 902is near End of Life, the smart memory chip 904 may disable the EHL probe902 and prevent the EHL probe 902 from firing.

In some implementations, the EHL probe 902 may include an internal powersource 908 such as a battery so that the smart memory chip 904 maymaintain a count of the number of times the EHL probe 902 has fired evenwhen the EHL probe 902 is disconnected from the electrical source 906.In some implementations the smart memory chip 904 may additionallyinclude a unique identifier, such as a serial number, so that the EHLprobe 902 is uniquely identified to the electrical source 906 when theEHL probe 902 is first connected to the electrical source 906. Theelectrical source 906 may use the unique identifier for purposes such asrecord keeping, performance analysis, or trouble shooting of faulty EHLprobes 902.

FIG. 9c is a flow chart of a method for using the EHL probe describedabove with respect to FIGS. 9a and 9b . At step 910, an EHL probe isconnected to the electrical source. At step 912, the electrical sourceretrieves a unique identifier from a memory of the EHL probe to identifythe EHL probe to the electrical source.

At step 914, the electrical source retrieves a count of a number oftimes the EHL probe has been fired from the memory of the EHL probe. Atstep 916, the electrical source determines whether the EHL probe is nearEnd of Life by comparing the number of times the EHL probe has beenfired to a threshold.

If the electrical source determines at step 916 that the EHL probe isnear End of Life, the electrical source disables the EHL probe at step917. Additionally, the electrical source may display a message such as“End of Life” or “Change Probe” to warn a doctor to dispose of the EHLprobe at step 918.

However, if the electrical source determines at step 916 that the EHLprobe is not near End of Life, the method proceeds to step 920 where theelectrical source sends a count signal to the memory of the EHL probe toincrement the number of times the EHL probe has been fired. At step 922,the electrical source fires the EHL probe. The method then loops to step914.

It will be appreciated that the order of one or more steps of the methoddescribed above with respect to FIG. 9c may be changed. For example, theelectrical source may fire the EHL probe (step 922) before incrementingthe number of times the EHL probe has been fired (step 920). Further, insome implementations, the method of FIG. 9b may be implemented inconjunction with a computer-readable storage medium comprising a set ofinstructions to direct a processor of the electrical source to performone or more of the above-described acts.

FIGS. 10a and 10b are a cross-section of an EHL probe 1002 including afusible link 1004 and a smart memory chip 1006. It will be appreciatedthat in implementations including both the fusible link 1004 and thesmart memory chip 1006, the fusible link 1004 may function as describedabove in conjunction with FIG. 8 to disable the EHL probe 1002 inresponse to a short blast of high current from an electrical source1008. Additionally, the smart memory chip 1006 may function as describedabove in conjunction with FIG. 9 to disable the EHL probe 1002 when thesmart memory chip 1006 determines based on a number of times the EHLprobe 1002 has fired that the EHL probe 1002 is near End of Life.

FIG. 10c is a flow chart of a method for using the EHL probe of FIGS.10a and 10b . At step 1010, an EHL probe is connected to the electricalsource. At step 1012, the electrical source retrieves a uniqueidentifier from a memory of the EHL probe to identify the EHL probe tothe electrical source. At step 1014, the electrical source measures aninterior resistance of the EHL probe to determine whether the EHL probehas been disabled.

If the electrical source determines at step 1014 that the EHL probe hasbeen disabled, the method proceeds to step 1015 where the electricalsource displays a message such as “End of Life” or “Change Probe” towarn a doctor to dispose of the EHL probe. However, if the electricalsource determines at step 1014 that the EHL probe has not been disabled,the method proceeds to step 1016.

At step 1016, the electrical source retrieves a count of a number oftimes the EHL probe has been fired from the memory of the EHL probe. Atstep 1018, the electrical source determines whether the EHL probe isnear End of Life by comparing the number of times the EHL probe has beenfired to a threshold.

If the electrical source determines at step 1018 that the EHL probe isnear End of Life, the method proceeds to step 1020 where the electricalsource sends a short blast of high current to the EHL probe to cause afuse within the fusible link of the EHL probe to open, thereby disablingthe EHL probe. At step 1022, the electrical source may display a messagesuch as “End of Life” or “Change Probe” to warn a doctor to dispose ofthe EHL probe.

If the electrical source determines at step 1018 that the EHL probe isnot near End of Life, the method proceeds to step 1024 where theelectrical source sends a count signal to the memory of the EHL probe toincrement the number of times the EHL probe has been fired. At step1026, the electrical source fires the EHL probe. The method then loopsto step 1016.

It will be appreciated that the order of one or more steps of the methoddescribed above with respect to FIG. 10b may be changed. Further, insome implementations, the method of FIG. 10b may be implemented inconjunction with a computer-readable storage medium comprising a set ofinstructions to direct a processor of the electrical source to performone or more of the above-described acts.

FIGS. 11a and 11b are a cross-section of an EHL probe 1102 including afirst fusible link 1104 and a second fusible link 1106. Generally, whenthe EHL probe 1102 is first fired, the first fusible link 1104 is blownso that the EHL probe cannot be reused (protecting its single usedesignation). Additionally, when an electrical source determines the EHLprobe 1102 is near End of Life, the electrical source may send a shortblast of high current to the EHL probe 1102 to blow the second fusiblelink 1106 as described above in conjunction with FIG. 8, therebydisabling the EHL probe 1102.

FIG. 11c is a flow chart of a method for using the EHL probe describedabove with respect to FIGS. 11a and 11b . At step 1110 an EHL probe isconnected to an electrical source. At step 1112, the electrical sourcemeasures an interior resistance of the EHL probe with respect to a firstfuse to determine if the EHL probe has been previously fired. If theelectrical source determines at step 1112 that the EHL probe has beenfired, the method proceeds to step 1114 where the electrical sourcedisplays a message such as “End of Life” or “Change Probe” to warn adoctor to dispose of the EHL probe.

If the electrical source determines at step 1112 that the EHL probe hasnot been previously fired, the method proceeds to step 1116 where theelectrical source measures an interior resistance of the EHL probe withrespect to a second fuse to determine whether the EHL has been disabledbecause it is near End of Life. If the electrical source determines atstep 1116 that the EHL probe has been disabled, the method proceeds tostep 1118 where the electrical source displays a message such as “End ofLife” or “Change Probe” to warn a doctor to dispose of the EHL probe.

If the electrical source determines at step 1118 that the EHL probe hasnot been disabled, the method proceeds to step 1120 where the electricalsource sends a short blast of high current to the EHL probe to cause thefirst fuse within the fuseable link of the EHL probe to open before theEHL probe is fired for the first time. At step 1122 the electricalsource monitors a number of times an EHL probe fires and power levelsused during firing of the EHL probe.

At step 1124, the electrical source compares the number of times the EHLprobe has fired and the power levels used during firing of the EHL probeto historical End of Life data for EHL probes to determine whether theEHL probe is near End of Life. If the electrical source determines atstep 1124 that the EHL probe is not near End of Life, the method loopsto step 1122 and the electrical source continues to monitor the numberof times an EHL probe fires and power levels used during firing of theEHL probe.

If the electrical source determines at step 1124 that the EHL probe isnear End of Life, the method proceeds to step 1126 where the electricalsource sends a short blast of high current to the EHL probe to cause thesecond fuse within the fusible link of the EHL probe to open, therebydisabling the EHL probe. At step 1128, the electrical source may displaya message such as “End of Life” or “Change Probe” to warn a doctor todispose of the EHL probe.

It will be appreciated that the order one or more steps of the methoddescribed with respect to FIG. 11c may be changed. Further, in someimplementations, the method of FIG. 11c may be implemented inconjunction with a computer-readable storage medium comprising a set ofinstructions to direct a processor of the electrical source to performone or more of the above-described acts.

Because of the delicate nature of small EHL probes and the long pathsthat may be required to insert an EHL probe through body channels orthrough sheaths or endoscopes, EHL probes in excess of 250 cm aredesirable. The EHL probes described above with respect to FIGS. 1-11 maybe constructed to allow for insertion of the EHL probe into channel inexcess of 250 cm by improving a linear strength of the EHL probe withoutsignificantly reducing the performance or flexibility of the EHL probe.

FIG. 12 is a side view of a reinforced EHL probe 1200. In oneimplementation, the linear strength of an EHL probe 1200 is improved byplacing a stiffening over-sheath 1202 partially over the EHL probe 1200.The stiffening over-sheath 1202 may be constructed of materials such asKynar®, Pebax®, or other similar materials.

In another implementation, the linear strength of an EHL probe 1200 isimproved by using non-kinking formulations of a polyimide sheathmaterial, such as those with thicker insulation, or ribbed or ringedareas along a length of a sheath or insulating material 1204. Examplesof these types of materials are provided by Micro Lumen.

In yet other implementations, the linear strength of an EHL probe 1200is improved by using an outer sheath 1204 of a polyimidesheath/insulation either coated or impregnated with lubricious materialssuch as Teflon or hydrophilic coatings. The more lubricious surface ofthe EHL probe would reduce a linear friction of the EHL probe as it isinserted through long channels.

In another implementation, the linear strength of an EHL probe 1200 isimproved by using conductor wire 1206 of special manufacture, such asstainless steel wire with copper coating. The stainless steel centerwould provide greater stiffness for push strength, and the coppercoating would provide for a less resistive current path. Because EHLprobes 1200 are often used in a radio frequency (RF) range, and RFcurrents tend to flow at the surface of a wire rather than at the coreof the wire, the added resistance of the stainless steel wire would notsignificantly affect the EHL probe 1200 performance.

In some embodiments, one or more of the implementations described abovefor improving the linear strength of the EHL probe 1200 may increase thelinear strength of the EHL probe 1200 by approximately 50%.

In yet another implementation, an EHL probe 1200 is constructed to allowfor insertion into long channels by rounding a tip 1208 of the EHL probe1200 as shown in FIGS. 13a, 13b, 13c, and 13d . By rounding the tip 1208of the EHL probe 1200, the tip 1208 of the EHL probe 1202 would be morelikely to slide and prevent the tip 1208 of the EHL probe 1202 from“digging” into tissue, or a sheath or a scope.

Electrical sources such as those described above with respect to FIGS.1-13 may use spark gap technology. The gaps used in spark gap technologymay be sealed, noble gas spark discharge tubes that have an approximatelife of approximately 400,000 to 500,000 discharges. After approximately400,000 to 500,000 discharges, the gaps can no longer “break over” at aproper voltage.

An electrical source used with an EHL probe may record information suchas a number of times a gap fires an EHL probe, a power of a gap when thegap files an EHL probe, a frequency of a gap firing an EHL probe, aunique identifier provided by an EHL probe, or any other informationthat may be useful to the electrical source in determining a remainingnumber of times a gap may fire an EHL probe. When the electrical sourcedetermines that a gap may no longer be able to file an EHL probe, theelectrical source may display a warning message indicating thatmaintenance or replacement of the gap is necessary.

In some implementations, the electrical source may include an internalpower source such as a battery so that when external power is notprovided to the electrical source, the electrical source is able tomaintain the recorded information regarding the gap. Additionally, insome implementations, the electrical source may communicate with acomputer so that the computer may retrieve the recorded informationstored at the electrical source for purposes of record keeping,performance analysis, or trouble shooting of the electrical sourceand/or an EHL probe.

It is intended that the foregoing detailed description be regarded asillustrative rather than limiting, and that it be understood that it isthe following claims, including all equivalents, that are intended todefine the spirit and scope of this invention.

The invention claimed is:
 1. An invasive lithotripter probe comprising:a water-tight flexible encapsulating member encapsulating a liquid; anda lithotripter tip positioned within the liquid encapsulated by thewater-tight flexible encapsulating member, the lithotripter tipcomprising: a first electrode; and a second electrode; wherein theinvasive lithotripter probe is dimensioned and configured to be threadedthrough a human vein or artery of a patient and delivered to a positionwithin an interior of a small lumen of a body organ of the patient suchthat the water-tight flexible encapsulating member is positioned againstthe interior of the small lumen of the body organ of the patient; andwherein the first and second electrodes are positioned on thelithotripter tip such that an electric arc between the ends of the firstand second electrodes causes an annular shockwave within the liquid toradiate radially in a direction that is transverse from the longitudinalaxis of the invasive lithotripter probe, such that while the invasivelithotripter probe is positioned within the interior of the small lumenof the body organ, the invasive lithotripter probe is configured todisturb tissue within the interior of the small lumen of the body organthat is positioned against the water-tight flexible encapsulating memberin a location substantially transverse to the longitudinal axis of theinvasive lithotripter probe.
 2. The invasive lithotripter probe of claim1, wherein the small lumen of the body organ is a fallopian tube.
 3. Theinvasive lithotripter probe of claim 1, wherein the first electrode ispositioned at a distal end of the lithotripter tip and wherein an end ofthe second electrode is coaxially aligned with an end of the firstelectrode.
 4. The invasive lithotripter probe of claim 1, wherein theliquid comprises saline.
 5. The invasive lithotripter probe of claim 1,wherein a distance between a tip of the first electrode and a point onthe second electrode that is closest to the tip of the first electrodeis between 0.006 and 0.100 inch.
 6. An invasive lithotripter probesystem comprising: a water-tight flexible encapsulating memberencapsulating a liquid; a lithotripter tip positioned within the liquidencapsulated by the water-tight water-tight flexible encapsulatingmember, the lithotripter tip and flexible encapsulating memberdimensioned and configured to be threaded through a human vein or arteryof a patient and delivered to a position within an interior of a humanvein, artery, or lumen of a body organ such that the water-tightflexible encapsulating member is positioned against the interior of thehuman vein, artery, or lumen of a body organ, the lithotripter tipcomprising: a first electrode; and a second electrode; and an electricalsource configured to charge the first electrode to a first polarity;wherein the first and second electrodes are positioned on thelithotripter tip such that an electric arc between the ends of the firstand second electrodes causes an annular shockwave within the liquid toradiate radially in a direction that is transverse from the longitudinalaxis of the invasive lithotripter probe, such that while thelithotripter tip and the watertight flexible encapsulating member arepositioned within the interior of the human vein, artery, or lumen ofthe body organ, the annular shockwave within the liquid causes thewater-tight flexible encapsulating member to disturb tissue within theinterior of the human vein, artery, or lumen of the body organ that ispositioned against the water-tight flexible encapsulating member in alocation substantially transverse to the longitudinal axis of theinvasive lithotripter probe.
 7. The invasive lithotripter probe systemof claim 6, wherein the electrical source comprises an electrohydraulicgenerator.
 8. The invasive lithotripter probe system of claim 6, whereinthe electrical source comprises a fusable link configured to disable thelithotripter tip.
 9. The invasive lithotripter probe system of claim 8wherein the electrical source is configured to monitor a number of timesthe lithotripter tip has fired and power levels used during firing ofthe lithotripter tip, and to determine when the lithotripter tip is nearEnd of Life based on the monitoring.
 10. The invasive lithotripter probesystem of claim 9, wherein the electrical source is further configuredto cause the fusable link to open in response to determining thelithotripter tip is near End of Life.
 11. The invasive lithotripterprobe system of claim 6, wherein the invasive lithotripter probe isdimensioned to be threaded through a human vein or artery.
 12. Theinvasive lithotripter probe system of claim 6, wherein the lithotriptertip is dimensioned to be delivered to a small lumen of a body organ. 13.The invasive lithotripter probe system of claim 12, wherein the smalllumen of the body organ is a fallopian tube.
 14. The invasivelithotripter probe system of claim 6, wherein the first electrode ispositioned at a distal end of the lithotripter tip and wherein an end ofthe second electrode is coaxially aligned with an end of the firstelectrode.
 15. The invasive lithotripter probe system of claim 6,wherein the liquid comprises saline.
 16. The invasive lithotripter probesystem of claim 6, wherein a distance between a tip of the firstelectrode and a point on the second electrode that is closest to the tipof the first electrode is between 0.006 and 0.100 inch.
 17. An invasivelithotripter probe comprising: a water-tight flexible encapsulatingmember encapsulating a liquid; and a lithotripter tip positioned withinthe liquid encapsulated by the water-tight flexible encapsulatingmember, the lithotripter tip comprising: a first electrode; and a secondelectrode; wherein the lithotripter tip and the body organ flexibleencapsulating member are dimensioned and configured to be threadedthrough a human vein or artery of a patient and delivered to a positionwithin an interior of a human vein, artery, or lumen of a body organsuch that the water-tight flexible encapsulating member is positionedagainst concretions within the interior of the human vein, artery, orlumen of the body organ; wherein the first and second electrodes arepositioned on the lithotripter tip such that an electric arc between theends of the first and second electrodes causes an annular shockwavewithin the liquid to radiate radially in a direction that is transversefrom the longitudinal axis of the invasive lithotripter probe, such thatwhile the lithotripter tip and the watertight flexible encapsulatingmember are positioned within the interior of the human vein, artery, orlumen of the body organ, the annular shockwave within the liquid causesthe water-tight flexible encapsulating member to disturb concretionswithin the interior of the human vein, artery, or lumen of the bodyorgan that are positioned against the water-tight flexible encapsulatingmember in a location substantially transverse to the longitudinal axisof the invasive lithotripter probe.